Automatic safety landing reversing propeller



Nov. 1, 1932. j

R. C. WILSON AUTOMATIC SAFETY LANDING REVERSIN G PROPELLEB 3Sheetsl-Sheet 1 Filed Feb. 12. 1931 Nov. 1, 1932. R. c. wmson AUTOMATICSAFETY LANDING REVERSING PROPELLER 3 Sheets-Sheet 3 FilecLFeb. 12. 1931Patented Nov. 1, 1932 UNITED STATES RICHARD 0. WILSON, OF MIAMI, FLORIDAAUTOMATIC SAFETY LANDING REVERSING PROPELIJER Application filed February12, 1981. Serial No. 515,329.

ihis-invention pertains to new and novel means for reversing a pluralityof airplanereversing the propeller blades for landing and toautomatically re-set the said blades 15 for forward flying.

A further object of the invention is to provide means for turning theropeller blades by the motion of the revolving shaft of the propeller bymeans which engages and turns at the blades of the propeller.

Anotherobject of the invention is to dispense with the use of sprin s inthe main operation of my improved device, thereby eliminatin a source ofdanger and unreli- 2 ability in ifi'erent temperatures and various kindsof climatic conditions. I

Another object of the invention is to provide means that may beinstalled and removed in exactly the same fit and key-way that is asused on any planes with non-reversible propellers upon which this deviceis to be installed.

Further objects of the invention are to rovide means adaptable for two,three and our :5 blade propellers; a practically automatic functioningof the reversing means to land and in resetting the blades for animmediate take-off if desired, with no care or attention of the pilotand without stoppage of the mofitor, allparts being easily accessiblefor inspection or replacing; the changing of the pitch while flying forspeed, in gaining elevation and for conserving fuel by properlyadjusting the pitch of the propeller after 4: flattening out-for flying.

The foregoing and such other objects as may appear from the ensuingdescription are accomplished by the combination, construction,arrangement and location of the several parts hereinaftermore fullydescribed, illustrated by the accompanying drawings, and moreparticularly-pointed out in the claims appended hereto, it beingunderstood that slight changes in the precise form, proportions andminor details of construction may be resorted to without departing fromthe spirit or sacrificing any of the advantages of the invention.

In the accompanying drawings forming a part of this specification itwill beseen that:

Figure 1 is an elevationof a portion of my improved propeller hub,showing a portion of the blade reversing mechanism n section.

Figure 2 is a central sectional elevation of the means shown in Fig. 1.m

Figure 3 is an elevation of the front portion of a part of the-propellerhub, showing the hub broken away.

Figure 4 is a fragmentary detail partly in section and partly inelevation, and

Figure 5 is a cross-section taken in the w plane of the dotted lines5'5, Fig. 1.

In the embodiment of my invention as illustrated it will be seen thatthe numeral 1 designates the propeller hub, shown as cylindrical, 76 andprovided at each of its ends with a tubular sleeve 2, adapted to receiveand retain a propeller blade. The hub is provided at its cen' ter with atransversely extending tapered socket 3, adapted to receive the mainengine or propeller shaft 4 to the threaded end portion of which the hubis secured by means of a threaded lock nut 5.

When normally flying the gearing is not engaged; as moving parts such asare atv present used are not used in connection with this type ofmachine. When it is desired to reverse the propeller, after nearing theground or other landing with the motor slowed down, the pilot s oves thereverse lever in the cockpit slightly ahead which allows the movement ofthe reverse mechanism. v a The link end 6 is lowered by the slightturning to the right of the reverse lever in the as cockpit; this lowersa link member '6' carrying the rack 7 which carries six flexible teethas shown at 8, these teeth engage conical teeth on the power wheel 9 asthis wheel is carried around by the hub 1 which-is as usual we versedthe requirement for this special deping back into safe? keyed to themotor shaft 4 by the key 10. The use of this key 10 is emphasized forthe reason that this mechanism is designed to replace the presentnon-reversible propellers, using the same taper fit shown at 10, in-thesuper parasol flier for experimenting on which the mechanism isdesigned, so that the present distance between the motor and thepropeller hub, in this case, is practically not increased and thechanging from the present type of non-reversible propeller to thisreversible one, or vice versa, is a matter of only a few minutes andrequires no shop or other expense.

Upon the engagement of the flexible teeth 8 with the conical teeth 12 ofthe power wheel 9 at its upper rim, themovementof this upper rim isretarded while the center of the power wheel 9 on its shaft 9 is carriedto the left, in this case, describing the dotted circle, as the powerwheel revolves around the motor shaft 4, the top of the power wheel 9 isturned to the right as long as its conical teeth 12 are meshed with theflexible teeth 8 carried by the reverse tooth rack 7. As there is apower wheel 9 for each propeller blade and one stationary tooth rack 7,motions of the power wheels are not continuous; the propeller blades allturning at once, 'when either of the power wheels isengaged, through theidler 14, secured at the front endof the motor shaft 4 to insure exactlysimilar pitch of the different propeller blades.

After six and a quarter revolutions of the.

power wheels 9, the propeller blades have resign for-this p ane. Uponthe desired movement of the blades the friction wheels 15, carried onone end only of the five sets of bolts 16, at positions 17, 18, 19, 20and 21 should impinge on the ends of their slots such as are shown bythe dotted lines 22, 23 and 24, Fig. 2, and by full lines 24 in the hub1, stopping the turning of the blades which are mounted inside ofthesleeves 2 and secured to the said sleeves by the through bolts 16, andsince the power wheels 9 cannot then turn, the flexible teeth 8 assumethe neutral positions with ends at 26, thus allowing the power'wheels tohe carried around the common or motor center without the retarded orturning motion of their upper rims. The functioning of this reversing,to the time of the bending clear of the flexible teeth requires abouttwo and a half seconds 9 with the present 260 R. P. M. of the slowedmotor, slowed down for the downward sweep to the landing site. Upon thebending to the position 26 of the flexible teeth 8, the rack is forcedupwards until drawn into the secure flying position as at first, by theslipposition of the reverse shaft and lever in' t e cockpit; thesecannot again be manipulated until the pilot shoves the reverse leverforward the required slight distance unlock it. This insures against Ireversing -slowed down motion. If desired to resume immediate flying thereverse lever is again freed by being forced ahead the required slightdistance'for unlocking after which it ,is turned slightly to theleft andthe resetting tooth rack 27 is raised slightly by the raising of thelink end 6 which causes the flexible teeth 28 to engage with the conicalteeth 12 of the power wheel 9 which causes an opposite direction of thepower wheels in the retarded movement of their rims, thus causing thepropeller blades carried by the sleeves to resume their originalposition, about sixty degrees around the shell of the hub 1, until theroller friction wheels 15 are stopped by the ends of their respectiveslots, and the flexible teeth 28 are bent. to positions 29 which stopsthe movement of the power wheels 9. Similarly to the upper reversingrack 7 performance, the curved flexible teeth ends at 29 cause theresetting rack 27 to be forced down to its former flying position clearof the conical teeth 12 on the power wheels 9 and the securing device onthe reverse lever in the cockpit looks it in the safe position until itis again desired-to reverse the propeller as at first described.

This automatic resumption of theflying position of the propeller bladesfor a quick take-off after landing is accomplished in about four secondsafter the control or reverse lever has been turned to reset for flying.

The-reverse or resetting movements of the propeller blades do notrequire the attention nor manipulation by the pilot, as the revolving ofthe propeller at the slowed down speed for landing furnishes the poweras above described. 'The flexible teeth furnish the automaticfunctioning in small designs of this ropeller and the use of a screwgovernor f not shown), operated by any suitable means in the largerdesigns furnish an accurate and positive stoppage of blade movement bymanipulating either up or down, the tooth rack 7 for reversing and toothrack 27 for resetting.

Movement of the propeller blades secured inside the sleeves 2 is causedby the power wheels 9 through their shafts 9 turning the gear wheels 30thus communicating movement to the front of the propeller throughthegears 30 on the front of the shafts 9 of the power wheels extendingthrough the hub 1. The actuated gear wheels 30' through their shafts 31operate the worm gears 32 which impart rotary movement to the racks 33carried by steel rings 34 riveted to the irmer end portion of eachsleeve 2. The double worm drive gears 32 provide an even ull on thesleeves carrying the propeller bla es and also furnish a positivelocking and securing device for the prevention of movement andchattering of the propeller blades. The undesired varying of pitch inthe propeller blades is prevented by the idler gear wheel 14 which isactuated by the forward gear 30 thus also imparting movement to all thepropeller m blades at each meshing of the flexible teeth 8 and 28 withthe conical teeth of the power wheels 9, thus providing a multi-drivearrangement in case of damage to one of the power wheels 9. The.flexible teeth are gov- 15 erned by springs 41 and 42 of sufiicientstrength to actuate the power for reversing the propellerblades withoutfail and also are designed to bend toneutral position when the bladeshave moved to the desired angle, so as to unmesh the reversing andresetting rack teeth from the conical teeth of the power wheels 9 andthrow their safety catches into play in the cockpit after the bladeshave been reversed or reset without any attention from the pilot otherthan the'manipulation of the control lever, all parts of the device areeasily and readily replaced and open for inspection and for oiling andcleaning. The bolts 16 carry the roller friction wheels 15 and alsosecure in place the wooden or steel propeller blades within the sleeves2. There are ten of these roller friction wheels 15 for overcomincentrifugal action. Two slides disposed at 3 and 37' assure contact ofmotor bracket 38 and sliding bracket 39 swinging at pivot 40. The halfellipse 40 formed in the lower end portion of the sliding bracket 39controls the stroke of the reversing tooth rack 7 and the resettingtooth rack 27.

It will be evident that the function of the coiled springs 41 and 42 isto keep the points of the teeth 8 and 28 at the proper pitch position toengage the conical teeth of the power wheel- 9, the tension of saidsprings being 45 regulated by the nuts, as shown in Fig. 1 of thedrawings, so that they allow the teeth to take the neutral position, at60. It will be obvious that where climatic conditions allow, the use offriction material may 59 be employed instead of the teeth.

Having thus described my invention, what I claim and desire to securebyLetters Patent is:

1. An airplane propeller having a hub, a

main shaft to which the hub is rigidly secured, a plurality of sleevesrotatably fitted within said hub, a pivoted and adjustable link:

' member carried at the inner side of the hub,

said link having an upper and a lower tooth-' 60 ed rack secured theretomeans disposed with- .in the hub and meshing with externally disposedmeans coacting with said racksand teeth for reversing the propellerblades with said sleeves. I

2. An airplane propeller having a hub, a

' in the hub and externally of said hub for immotor shaft rigidlysecured to the hub, a plurality of sleeves rotatably secured within saidhub, a pivoted and adjustable link member carried at the inner side ofthe hub, an upper and a lower rack member secured to the outer face ofsaid link, flexible teeth carried by each rack, and meansv formed oneach sleeve meshing with externally disposed means and coacting. withsaid racks and teeth for reversing the propeller blades disposed withinthe sleeves. I

I 3. An airplane propeller having a hub, a

motor shaft rigidly secured to the hub, a plurality of sleeves'rotatablysecured within said hub, a pivoted and adjustable. link member carriedadjacent said hub, an upper and a lower toothed rack secured to thelink, and

means coacting with internal and external means and with said racks forreversing the propeller blades to an extent of about sixty degrees.

4. An airplane propeller having a hub, a motor shaft to which the 'hubis fixedly secured, a plurality of sleeves rotatably securedwithin saidhub, a pivoted and adjustable link member carried adjacentthe inner sideof thehub, means for adjusting said link member, an upper and a lowerrack member formed with the link member, and means dis posedwithin andexternally of the hub cothe hub for reversing the propeller.

5. An airplane propeller having a hub, a main shaft to which the hubis-fixedly secured, a plurality of sleeves rotatably secured within saidhub, a propeller blade fittedwii'hin each sleeve, a pivoted andadjustable link member carried at the rear of said hub. a plu rality ofrack members secured to said link, a plurality of gear wheels carriedatthe front of said hub, a plurality of screw gears meshing with racksdisposed within the hub, means for adjusting said link member, and meanscoacting with said link member for reversing said propeller blades. I

6. An airplane propeller having a hub, a motor shaft fixedly secured tothe hub, a plurality of sleeves rotatably secured within the hub. a linkmember pivotally secured at the rear side of the hub. a gear wheelcarried at the rear side of the hub, gear wheels carried at the frontside of the hub, and means carried at the upper and lower portion of thelink and coacting with means disposed'withm parting a reverse movementto the, propeller.

7. The. combination with an airplane propeller hub, of a plurality ofpropeller blades rotatablymounted W thin the hub. a plurality ofrotatable sleeves mounted within the hub, gearing for rotating saidblades, said gear-' ing comprising a link member having-an upper and alower flexible toothed rack secured to said'links, gear wheels securedat the front and rear of said-hub, and means disposed with p I actingwith said link member and carried by the hub and externally thereofcoacting with the said racks for reversing said propeller blades. i

8. The combination with an airplane pro- 5 peller hub, of a plurality ofpropeller blades rotatably mounted within the hub, a plurali ofrotatable sleeves mounted within the hu gearing for rotating saidblades, said gearing comprising a link member formed with an upper and alower rack provided with flexible teeth, gear wheels secured at thefront and rear of said hub, and means disposed internally and externallyof the hub coacting with the link member for reversing the saidpropeller blades. V

9. The combination with an airplane propeller of a hub, a plurality ofsleeves rotatably mounted within the hub, a propeller blade fixedlysecured within each sleeve, a

pivoted and adjustable link member secured adjacent the rear. of thehub, said link carrying an upper and a lower flexible toothed rack,means for adjusting the link member, gearing for rotating said blades,said gearing comprising a gear wheel disposed at the rear of the hub,gear wheels disposed at the front of the hub, a plurality of screw gearsmeshing with racks formed on the outer face of each sleeve and disposedwithin the hub, and means carried by the link member and meshing with agear for imparting reverse movement to said blades.

y 10. A propeller having a hub, a motor shaft fixedly secured to saidhub, a plurality of 39 sleeves rotatably secured within the hub, a

propeller blade mounted in each sleeve, a link member pivotally securedto the rear of the hub, and means cooperating with said link member forchanging the pitch of each blade an after flattening out for flying.

11. A propeller having a hub, a motor shaft fixedly secured to said hub,a plurality of sleeves rotatably mounted within the hub, a propellerblade mounted within each sleeve, a

- link member pivotally secured at the rear of said hub, an upper andlower set of flexible teeth carried by the link member, and meanscoacting with said teeth for reversing and resetting said propellerblades.

RICHARD 0. WILSON.

